The present invention relates to a process for producing a particulate wax composition having improved free flowing properties and/or hardness from wax materials having a substantial content of low melting point soft waxes in addition to higher melting point and/or harder waxes.
Normally the incorporation of soft, low melting point waxes in waxes consisting of or comprising a higher melting point and/or harder wax component results in wax powders of which the particles have a reduced hardness and a tendency to become caked together. Such poor free flowing and non-caking properties are undesirable from the point of view of handling the waxes. Yet it may be desirable to incorporate substantial quantities of low melting point soft waxes into powderous wax materials, e.g. wax blends either when it is positively desirable to produce a blend having a lower softening temperature or other characteristics ascribable to the low melting point soft waxes or alternatively, when the low melting point soft waxes or alternatively when the low melting point soft waxes are readily available and are not objectionable from other points of view regarding the intended use of such waxes.
Accordingly it is an object of the invention to provide a process which permits the incorporation of such low melting point soft waxes into wax mixtures or blends, whilst mitigating the adverse effect thereof on the free flowing properties and hardness of the powder. Hardness of the powder in the present context is at least in part apparent from the observable tendency of the powder particles to cohere when pressed together.
The present application describes the manufacture of such powders having particle sizes between 3 microns and 3 mm, preferably between 5 and 100 microns. It has now been found that powders of the same compositions are superior if they are predominantly composed of coarser particles normally between 0.10 and 3 mm and in particular between 0.15 and 2 mm, more preferably between 0.2 and 1 mm. In such powders the particles have a much reduced tendency towards cohesion by electrostatic attraction. Yet these powders are commercially perfectly acceptable for the important uses to which these powders can be put.